Lawyer, advocate, barrister difference

In Pakistan, the terms “lawyer,” “advocate,” and “barrister” are often used interchangeably, but there are some subtle differences between these terms.
A lawyer is a general term used to describe anyone who is qualified to provide legal advice and represent clients in court. In Pakistan, lawyers must have a law degree and be licensed to practice by the Pakistan Bar Council.
An advocate is a lawyer who is authorized to represent clients in court. In Pakistan, advocates must be licensed by the Pakistan Bar Council and have completed a one-year apprenticeship under a senior advocate or a judge of the high court.
A barrister is a type of lawyer who qualified BPTC  in UK, and have completed a one-year apprenticeship under a senior barrister or a judge in one of the inns of court.